A. Technical Field
The present invention relates to signal processing of sensors and, more particularly, to systems, devices, and methods of reducing quadrature error in oscillating sensor circuits.
B. Background of the Invention
Quadrature error refers to an undesired spurious signal that is one of the most important causes of saturation in the readout chain of angular rate sensors, such as gyroscopes. Since quadrature error compromises the performance of the sensor, it is desirable to completely eliminate quadrature error. Existing compensation schemes that reduce quadrature error oftentimes add circuitry, including dedicated electrodes, into the sensor to compensate for the effects of quadrature error. Such a dedicated circuit approach, however, limits the dynamic range of the sensor, wastes valuable silicon area and testing time and, ultimately, adds significant cost. A need exists to eliminate the non-idealities associated with quadrature error from oscillating sensor circuits without negatively impacting the dynamic range of the sensor.